The long term objective is to advance the fundamental and quantitative understanding of biologically significant macromolecules. Areas of study include equilibrium conformational statistics, the dynamical mechanisms through which biopolymers change configuration, and the interactions of biopolymers with each other and with small molecules and ions. Our goals for the immediate future are: 1. Calculate the counterion distribution surrounding DNA by means of modified applications of the Poisson-Boltzmann approach and thereby account for dielectric heterogeneity and charge density fluctuations. 2. Determine the change in conformation and stability of DNA induced by charged binding agents, and the dynamical processes that bring about these changes, through a combination of analytical calculations and simuations of Brownian dynamics. 3. Improve calculations of relaxation properties such as the stress relaxation modulus and birefringence relaxation times, of DNA and other stiff chain macromolecules, through the incorporation of advances in the dynamical theory of constrained polymers. 4. By Brownian dynamical simulations and modeling based on the generalized Langevin equation, determine the nature of conformational relaxation and diffusion in concentrated solutions of chain polymers.